Pretreated natural resin and method of utilizing the same



sTAT PATENT PRETREATED NATURAL RESIN AND IWETHOD F UTHLIZING THE SAlVmIsrael Rosenblum, Jackson Heights, N. W.

No Drawing. Application August 25, 1032, Serial The present inventionrelates to a novel precompound appears to remain with the rosin.treatment for an acidic natural resin whereby Thus, I have found thatwhen rosin is heated its acidity is reduced, and to the production ofwith formaldehyde to 250 C. and kept at such oil-soluble syntheticresins with such pro-treated temperature for two hours, about 1% offormalnatural resin. dehyde based upon the weight of the rosin, is 5 Itis known to produce oil-soluble resins conretained by the latter.Whether the formaldetaining a condensation product of a phenol and hydeis chemically combined with the rosin or is an aldehyde and having acomparatively low only in physical admixture therewith, I am not acidnumber, by condensing phenol and formalprepared to say; it appearshowever that, in view it dehyde at temperatures of about 100 C. in theof the reduction of the acid number, which is presence of rosin or othernatural resin and then far more than can be accounted fo by the mereneutralizing the mass at higher temperatures heating of the resin (the ay of a acidic with a polyhydrie alcohol, such as glycerol. In naturalresin is slig tly reduc y dry-distilling such known process the phenoland formaldeor cracking), and in view also of the fact that it hydecondense readily in the presence of the prolonged heating at 250 C. doesnot expel the rosin at a comparatively low temperature, the remainingpor i n of fOrmaJdehyde, chemical water and excess formaldehyde beingdriven on combination of some kind has taken place. after thecondensation has gone as far as it can A natural resin so pretreated maywith adbe made to gounder practical conditions, the vantage be employedin association with synto mass being then heated with glycerol to newthetic resins. Thus a phenol, substituted or untralize the same. I havenow found that if the substituted or mixtures of the same, and a canaturalresin, and particularly colophony, is first bonyl-containingcompound may be condensed treated with a carbonyl-containing compound,at about 100 C. in the presence of theformaland especially formaldehyde,at high temperadehyde-treated rosin at atmospheric pressure or at tures,the acidity of the natural resin is reata sligh y hi t p atu a up "a 0 Wduced to a very considerable degree while the pheric pressure. After theinitial condensation resinous mixtures obtained by causing a phenol issubstantially completed the water and unand a carbonyl-containingcompound to conreacted volatile material are driven oil with or dense inthe presence of such pre-treated resin without the aid of vacuum. Themass is then has not only a lower acid number but also other slowlyfurther heated and is neutralized by esterimproved properties ascompared with a resin ification with a polyhydric alcohol or with a madeunder similar conditions with a natural partial ester of a polyhydricalcohol. While the resin not so pro-treated. polyhydric alcohol may beadded to the mixture According to the present invention, an acidic ofphenolic condensate and rosin at high temttt natural resin, such asrosin, is treated with an peratures, e. g. about 250 C., I prefer to addaqueous or solid aldehyde (e. g. paraformalde the same at about 160 0.;if desired, the alcohol hyde) with or without pressure by heating thesemay be mixed with the phenol, aldehyde, and materials slowly to atemperature of about 250 rosin at the beginning of the reaction. It ap-C'. or above. The time required to reach this pears that at the lowertemperatures the phenoltemperature will depend upon the mass of the iccondensate is in a more reactive state, while 40 mixture. I prefer tokeep the mixture at the the polyhydric alcohol tends to form largerquanmaximum temperature for about two hours, altities of partial esterswith the rosin, so that the though it may be subjected to suchtemperature formation of mixed polyhydric alcohol esters of for longeror shorter periods depending upon the the phenolic condensate, which isacidic in char conditionsunder which the treatment takes place. acter,and of the rosin is promoted. Whatever I have found that by suchtreatment the acid the true nature of the chemical reactions innumber ofthe rosin may be reduced from about volved may be, I have found thatresins of bet- 178 to about and even lower, the acidity ter viscosity insolution and lower acid number falling along an almost straight line.Thus are obtained by causing the alcohol to act at W upon heating rosinwith about 5% of its weight lower temperatures, e. g. -180 C. 50

. I of formaldehyde, the acid number of the rosin The condensation ofthe phenol and aldehyde falls from about at 140 C. to 164 at 160 (3.,may take place in the presence or absence of a 153 at C., 145 at 220(3., and 135 at 250- C. catalyst; I prefer, however, to employ acatalyst During the treatment a part of the formaldein the form of azinc compound such as zinc oxide, hpde is driven off, but a certainamount oi such hydroxid a nzoate abietate. stearate.

oleate, palmitate, tungate. Any of the corresponding compounds ofcalcium, barium, strontium, lead, cobalt, nickel, manganese etc. mayalso be used. The compounds of the alkali metals may be used but do notusually give the best results.

The natural resin can be pre-treated with the formaldehyde underelevated, normal or reduced pressures in the presence of a solvent, suchas mineral spirits, turpentine, toluol, xylol etc., which can beexpelled at elevated temperatures. The great reduction in the acidity ofrosin, for example, by treatment with formaldehyde at elevatedtemperatures will be evident from the following experiment:

Example 1 10 lbs. of commercial rosin having an acid number of 178 wereheated with 5% of formaldehyde, based upon the weight of rosin, in theform of the 40% aqueous solution. The mixture was kept under pressureuntil the temperature of 110 C. was reached. The temperature was thenslowly raised, water and excess formaldehyde escaping until thetemperature of 250 C. was reached. The mass was kept at this temperaturefor four or more hours. At the end of four hours at 250 C. the acidnumber was found to be 135. The gradual reduction in the acid number ofthe rosin began at a temperature of about 160 C., the acid numberfalling along almost a straight line to a value of 135 at 250 C.

The so pre-treated rosin or other acidic natural resin is, as aboveindicated, advantageously employed for the production of oil-solublephenolaldehyde resins of low acid number. The phenol, aldehyde andnatural resin are mixed and heated at a temperature of to 130 C. with orwithout pressure for several hours. The temperature is gradually raisedto remove water and uncombined phenol and aldehyde. The dehydration iscomplete at about 160 C. At this temperature vacuum can be applied for afew hours to expel the last portions of volatile material, especiallyuncombined phenol. With the temperature still at 160 C. an amount ofglycerol equivalent to about 9% of the weight of rosin is added and thetemperature is then slowly raised to 250 C. during a period of aboutfour hours and the esterification completed at this temperature. Themixture may be agitated during the heating and either vacuum or pressuremay be applied as desired.

My invention will be described in greater detail with the aid of thefollowing examples which are given by way of illustration only and arenot to be construed as defining the limits of the invention.

Example 2 Example 3 1000 parts of formaldehyde pre-treated rosin, 131parts of phenol and 158 parts of aqueous formaldehyde (corresponding to63 parts of formaldehyde) are condensed under pressure at C. and themass then dehydrated up to about 160 C. 90 parts of glycerine are addedat this temperature and the mass slowly brought to 250 C. and maintainedat such temperature until a resinous mass of low acid number (about 8)is obtained. I

' Example 4 1000 parts of formaldehyde pre-treated rosin, 170 parts ofphenol and 81 parts of paraformaldehyde are heated and esterified with90 parts of glycerine as above described. A mass is obtained which, inspite of the increased content of phenolic resin, is soluble in oil andis of low acid number.

Example 5 1000 parts of formaldehyde pre-treated rosin, 150 parts ofamyl phenol and 82 parts of paraformaldehydeare condensed at C. until aresinous phenol-formaldehyde condensate is obtained and the mass thendehydrated up to 160 C. There are then added 90 lbs. of glycerol and theheating continued as above.

Example 6 1000 parts of formaldehyde pre-treated rosin, 50 parts of amylphenol, 50 parts of (ordinary) phenol and 38 parts of paraformaldehydeare condensed according to any of the procedures above described andthen esterified with 90 parts of glycerine which are added at about 160C., after which the temperature is slowly raised to about 250 C. andmaintained at such temperature until a homogeneous resin of low acidnumber is obtained.

Example 7 1000 parts of formaldehyde pre-treated rosin, 75 parts of amylphenol, 75 parts of (ordinary) phenol and 57 parts of paraformaldehydeare treated as above described and yield a resin of low acid number andexcellent solubility in oils.

In all of the above examples a catalytic agent may be employed, such asa small quantity of zinc oxide.

The resins obtained in accordance with the invention are characterizedby an unusually low acid number, the phenol-aldehyde condensate, whichis acidic in nature, appearing to have a lower acid number when producedin accordance with the above examples. The resinous products obtainedare also harder and more alkali-proof than similar resins heretoforeproduced from a phenol-aldehyde condensate, rosin and glycerol.

The phenol employed may be ordinary phenol,

a substituted phenol, preferably in the para position, such as cresol,amyl phenol, butyl phenol, phenyl phenol, etc., or mixtures of suchphenols. The formaldehyde for pre-treating the natural resin may bereplaced in whole or in part by other aldehydes, such as acetaldehyde,or by ketones, such as acetone, but the use of formaldehyde ispreferred. The action of the formaldehyde on the natural resin becomesnoticeable at about C. and increases steadily from this temperature toabout 250 to 260 C.

In place of glycerol other alcohols, preferably polyhydric, may be used,e. g., glycol, mannitol, etc. Other variations may be resorted to withinthe scope of the appended claims without departaldehyde to suchpre-treated rosin and heating aldehyde, adding a polyhydric alcohol inquantities suflicient substantially to neutralize the mass, and heatingthe mixture at about 260 C. until the reaction is substantiallycompleted and a fusible, soluble, resinous mass is obtained;

2. The method which comprises heating rosin with formaldehyde up totemperatures of about 250 C. until the acid number 01 the resin is about135 or below, cooling the rosin and adding thereto a phenol andformaldehyde, heating the mixture at approximately 100 to 130 C. untilthe phenol and formaldehyde are condensed, raising the temperature toapproximately 160 0., adding approximately 9% of glycerol based upon theweight of rosin, slowly raising the temperature to about 250 'C., andcontinuing the heating at approximately such temperature until thereaction is substantially completed and a fusible, soluble, resinousreaction product is obtained.

3. The method which comprises heating rosin with formaldehyde to about250 C. until the acid number of the rosin has been reduced to about 135,mixing such pre-treated rosin with a phenol substituted by a hydrocarbonradical of the group consisting of saturated aliphatic radicals having,

4 A product of the process defined in claim 1.

5. A product or the process defined in claim 3.

ISRAEL ROBENBLUM.

